Correct dewarping settings for hikvision fisheye camera in ptgui?

[Andy]

Hi everyone,

I'm struggling to get fisheye camera images properly dewarped in PTGUI and could really use some help.

I'm working with Hikvision DS-2CD63C5G0-IVS cameras. According to the datasheet, they use a 1/1.7" Progressive Scan CMOS sensor with a focal length of 1.29 mm. 

Here’s an example image from the camera: https://knuts.be/ptgui/snap.png

This is my first time using PTGUI, so I’m probably missing something basic. Could anyone guide me on the correct settings or workflow to get these images dewarped correctly? Any tips or step-by-step instructions would be greatly appreciated!

Thanks in advance for your help!

[John Houghton]

Andy,  It's not possible to accurately dewarp your single fisheye image without a good set of lens parameters that correct the lens distortions.  In order to determine these parameters, you should perform a calibration exercise, as described in the FAQ item https://ptgui.com/support.html#6_3 .  In the great outdoors or in a large indoor venue, shoot a full 360 degree panorama with four shots around, rotating the camera about the front of the camera lens.  In the PTGui project, avoid putting control points on nearby features.  For your single image, I simply pretended it was from a camera with an 8mm fisheye lens with a field of view of 180 degrees, setting a crop circle on the edge of the image circle (select Advanced mode to get access to the Crop tab).  My project file is attached.  Load it into the same folder as the camera image file and open the project with File/Open.  The output I set to a 360x180 equirectangular projection and I rotated the output image down by -90 degrees (as it was shot pointing down at pitch = -90 degrees).

See the video tutorials on the PTGui web site under the "Learn" heading.

John